This invention relates to whole blood collection devices for use in blood sampling. More particularly, the present invention relates to a collection device and method that allows whole blood to be collected precisely and reliably at a remote site and then shipped to a central laboratory for analysis.
In the past, it has been common practice for a physician to require an individual to come to a laboratory or office to have whole blood drawn for clinical analysis. This represents a substantial inconvenience to the individual, however, it has been considered a necessary prerequisite for obtaining a suitable blood sample for many types of blood tests. A need presently exists for an improved system that overcomes this inefficiency by allowing a patient to obtain a blood sample at home, for example, and to then ship the self-collected sample to a clinical laboratory for testing. In addition, many physicians could benefit from a reliable blood collection device that allows for minimally invasive collection of blood samples in their office during patient visits.
There is an ongoing need, therefore, for a reliable blood testing apparatus that can be used by an individual without assistance of medical personnel or in a clinical office setting, which provides a reliable, minimally invasive means of collecting blood samples for off-site clinical analysis. The present invention fulfills this need.
The blood collection device of the present invention is a compact, self-contained, handheld blood sample collection and storage device that can be conveniently used by an individual without assistance of medical personnel. The blood collection device is designed to collect a specific quantity of blood that is sufficient for selected clinical blood analyses. The device can be configured to collect enough blood for a single blood clinical analysis or for several analyses. Preferably, the device is configured to collect a sufficient quantity of blood for a single analytical test protocol. The device of the present invention is also a storage device for safely and reliably preserving the collected blood sample during shipment to a clinical laboratory for analysis.
In a preferred embodiment described below, the device is configured to collect a precisely metered volume of whole blood without the need for training, and without the need for the user to perform complex techniques. The system can dilute the whole blood and seal the diluted blood in the device when the user simply turns a lever. By diluting blood at the point of collection, blood stability is improved. Blood dilution also improves the likelihood that the analyzing laboratory will have an adequate physical sample of liquid with which to work, once the specimen reaches the laboratory for analysis. If desired, a stabilizing composition can be placed in the diluting liquid to stabilize specific blood components prior to analysis.
The present whole blood sample collection device defines a reservoir for a collected whole blood sample, a metering chamber that initially receives the whole blood sample and empties into the reservoir, and a fill port that communicates with and empties into the metering chamber. The collection device is also provided with a movable seal or gasket that can isolate the reservoir from the metering chamber. When the seal or gasket is in a fill position, the reservoir is isolated from the metering chamber and a liquid flow passageway is defined between the fill port and the metering chamber so that a whole blood sample can be received into the metering chamber via the fill port. When the seal or gasket is in an intermediate position, the metering chamber can be isolated from the fill port as well as from the reservoir. When the seal or gasket is in a closed position, the seal isolates the fill port from the metering chamber but a fluid flow passageway is defined between the reservoir and the metering chamber so that there exists fluid flow communication between the reservoir and the metering chamber, and the blood sample contained in the metering chamber can be swept into the reservoir for storage and subsequent analysis.
The whole blood sample collection device of the present invention also includes a mechanism for delivery of anticoagulant to the blood sample, inasmuch as an anticoagulant is generally required for most analyses that can be performed on blood stored for a period of time before testing. In one embodiment of the invention, the anticoagulant is supplied to the blood by passing the blood through a pad that has been impregnated with anticoagulant. The anticoagulant impregnated pad is integrally positioned within the blood receiving portion of the device so that blood must flow through the pad to enter the sample storage and dilution chamber of the device. In another embodiment, interior surfaces of portions of the device that define a blood sample passageway within the device, and that are designed to contact the blood sample are coated with an anticoagulant, so that as the blood contacts these surfaces an anticoagulant is delivered to the blood sample. The anticoagulant coated surfaces can be used in conjunction with an anticoagulant impregnated pad, or the coated surfaces themselves can act as the sole anticoagulant delivery source in the device.
A surface wetting agent such as a nonionic surfactant can also be included in the anticoagulant coating. The wetting agent can serve a dual purpose of promoting efficient flow of blood into the sample storage chamber and facilitating the deposition of a substantially uniform anticoagulant coating on the blood contact surfaces of the device during manufacture.